Huang Ting, Yeung Kan Kan, Li Jingwei, Sun Honglin, Alam Md Masruck, Gao Zhaoli
Biomedical Engineering Department, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
CUHK Shenzhen Research Institute, Nanshan, Shenzhen 518057, China.
Nanomaterials (Basel). 2022 Jul 29;12(15):2620. doi: 10.3390/nano12152620.
Field-effect transistors have attracted significant attention in chemical sensing and clinical diagnosis, due to their high sensitivity and label-free operation. Through a scalable photolithographic process in this study, we fabricated graphene-based ion-sensitive field-effect transistor (ISFET) arrays that can continuously monitor sodium ions in real-time. As the sodium ion concentration increased, the current-gate voltage characteristic curves shifted towards the negative direction, showing that sodium ions were captured and could be detected over a wide concentration range, from 10 to 10 M, with a sensitivity of 152.4 mV/dec. Time-dependent measurements and interfering experiments were conducted to validate the real-time measurements and the highly specific detection capability of our sensor. Our graphene ISFETs (G-ISFET) not only showed a fast response, but also exhibited remarkable selectivity against interference ions, including Ca, K, Mg and NH. The scalability, high sensitivity and selectivity synergistically make our G-ISFET a promising platform for sodium sensing in health monitoring.
场效应晶体管因其高灵敏度和无需标记的操作，在化学传感和临床诊断中备受关注。通过本研究中的可扩展光刻工艺，我们制造了基于石墨烯的离子敏感场效应晶体管（ISFET）阵列，该阵列能够实时连续监测钠离子。随着钠离子浓度的增加，电流-栅极电压特性曲线向负方向移动，表明钠离子被捕获，并且在10⁻⁶至10⁻¹M的宽浓度范围内均可被检测到，灵敏度为152.4 mV/dec。进行了时间相关测量和干扰实验，以验证我们传感器的实时测量和高特异性检测能力。我们的石墨烯ISFET（G-ISFET）不仅显示出快速响应，而且对包括Ca²⁺、K⁺、Mg²⁺和NH₄⁺在内的干扰离子表现出显著的选择性。可扩展性、高灵敏度和选择性协同作用，使我们的G-ISFET成为健康监测中钠离子传感的有前途的平台。
